What makes bullets tumble? did some training, they told me some were tumbling.

[mallen]

What makes bullets tumble? did some training, they told me some were tumbling. some were not.

[silverjay]

My 9's will tumble when sized to .356.

[fouronesix]

Tumbling is usually the wrong description. If some were cutting elongated holes in the target and some not, most likely they were simply unstable and not tumbling. They were spinning but unstable in flight with the front portion yawing around its axis. A bullet that truly tumbles (end over end) in flight is fairly rare.

[mallen]

ok, so, why does that happen? what do i do to fix it?

[Digital Dan]

Shorter bullet or drive it faster. What are you shooting, both gun and load?

[fouronesix]

I assume you are shooting a 9mm handgun with cast bullets. Of all the threads about problems on this forum, two of the most common seem to be about 9mm handgun cast bullet leading and/or accuracy. How you fix the issue of leading and/or stability of cast out of the 9mm handgun? Good question and others will have many more and probably better ideas than I.

But, here's my take on it. The leading and instability/accuracy issues are probably interrelated. Either the unstable bullets are not spinning fast enough or have been compromised by the leading or both. Solve the leading and choose a load that gives sufficient velocity (thus spin rate) to fully stabilize the bullets. Don't blow up the gun.

I shoot a lot of different firearms of all types with both jacketed and cast bullets. The only ONE that I refuse to reload for or piddle with is my 9mm handgun. High quality, super reliable self defense ammo is still relatively cheap and widely available.

[Djones]

Are you using "tumble" lube?

[mallen]

why do people keep telling me to shoot faster..... i feel safe at just above minimum charge. chuckles


Are you using "tumble" lube?

yes

[Digital Dan]

Safety has little to do with bullet stability. You aren't going to get a good answer until you cough up some details. WHAT ARE YOU SHOOTING?

[mallen]

9mm fns slugged at .355. 3gn of imr 700x. bullet sized at .357.

[btroj]

How do they know they are tumbling?

I would expect the bullets are undersized for you bore. Did you get any leading in the barrel? I can shoot 25 rounds of .356 bullets thru my GP 100 and get keyholes almost every shot after that. Rifling fills with lead the bullets don't get enough spin to stabilize.

[Wayne Smith]

WHO told you that they were tumbling?? Unless you have a target with a hole that looks like a sideways boolit they are not tumbling. So, unless that is true, we really don't know what is going on. A severely bad bore can cause a boolit to tumble, like a shot out military rifle. Otherwise, it is very unusual.

[mallen]

maybe that was it. I was getting some leadding after about 100 to 200 shots.

.355 barrel, .357 bullet. iv got another thread to try to fix the leadding problem. ill have to revisit this one after i get the leadding issue fixed.

[mallen]

they could see it in the target.

[Dave C.]

You need a shorter boolit, does not need to be lighter. Or you need to drive it faster.

Dave C.

[mallen]

facepalms, more speed. people keep telling me that. lol, im comfortable at slow speeds.

[Driver man]

I would up the powder charge to 3.3 grains.

[mallen]

just double checked the website. im closer to 900. 3.4 gns will put me at 1003 fps. maybe a tad faster. bigger bullet, slightly shorter overall case length

[btroj]

Hard bullets sized too small loaded over light charges are a great way to lead a barrel and give key holing bullets.

Softer alloy, larger diameter, and more powder could cure the problem. It might even be just one of these variables.

[KYCaster]

What weight bullet?
What gun?
What barrel?
What twist rate?
What speed?

Need more info.

Jerry

[mallen]

What weight bullet? 125 (scales at 128)
What gun? fns
What barrel? .355
What twist rate? 1 in 10
What speed? 900 fps

Need more info.

Jerry

well. wiggled the bullet out as gently as i could. seems seating the bullet made it a bit oblonged shaped. quite a bit. smaller than the slug at oen diameter, a .001 smaller at another diameter. adds leaddding. don't think they tumbled till there was leadding

[btroj]

What alloy? That is a huge factor. Too hard isn't any better than too soft. Hard and undersized will almost always lead.

[mallen]

range lead and 5% pewter.

[mallen]

I don't think dillon makes a "m" die for the square deal b

[btroj]

Drop the pewter. My range lead, from an outdoor range, water drops to 24 BHn and shoots great in my handguns. I personally think adding just 1/2 percent tin would be enough.

My dillon funnel opens case mouths just fine for 9mm. You might need to adjust things to find a combination that works.

Try changing a few things and see what happens. Change just one thing at a time. More crimp, less crimp, more mouth bell, less mouth bell, harder and softer alloys. Load a hundred of each and see what happens. This is how you learn. This is also how you cater to that guns likes and dislikes.

[mallen]

when i ran just the range lead alone, i got horible leadding. came out a smooth bore after 100-200 shots

[btroj]

Try water dropping them. Or sizing bigger. Many here size to .359 for 9 mm, I know I have been.

[mallen]

those might be smaller. hard to tell. don't use that mold anymore

[MT Chambers]

a) bullet fit is wrong
b) bullet is too small and/or too hard
c)bullet wrong for twist
d) bore ride portion of longer bullets is small

[mallen]

1 and 10 twist. not sure how to fit bullets to twists.


don't understand d

bullet is .002 bigger than slug, but might be getting swagged upon insertion

[fredj338]

Undersized bullets or bullets to heavy for the twist rate moving too slow. You see it a lot with minor 9mm & 147gr. Put some powder in there. If you are at a training class, unless it is a gamer class, you want ammo that mimics what you carry IMO.

I don't think dillon makes a "m" die for the square deal b
FWIW, Why I don't recommend the SDB, it limits what & how you can reload. If you pull a loaded round & measure it & the bullet is smaller than when yo useated it, polish the powder thru expander down 0.001". You may have to get another one if yo udo this & then want to reload jacketed.

[mallen]

Undersized bullets or bullets to heavy for the twist rate moving too slow. You see it a lot with minor 9mm & 147gr. Put some powder in there. If you are at a training class, unless it is a gamer class, you want ammo that mimics what you carry IMO.

FWIW, Why I don't recommend the SDB, it limits what & how you can reload. If you pull a loaded round & measure it & the bullet is smaller than when yo useated it, polish the powder thru expander down 0.001". You may have to get another one if yo udo this & then want to reload jacketed.

sdb is great for folks on a budget. I do plan on upping the powder once i see how it does if i can get the swagging done with. im affraid i do not understand your advice on polishing the expander. lowering the diameter, would make my case dia smaller, thus it would swag the bullet more?

[MBTcustom]

The reason why people keep telling you to shorten the boolit or push it faster, is because one of the possible causes of a tumbling boolit is that you are not giving it enough RPMs to stabilize it. If that is the case, then there are only two options:
1. Push it faster in order to spin it faster.
2. use a shorter boolit that naturally requires less RPM's to stabilize.
Some argue that there is no such thing as overstabilizing a projectile. As long as you meet the minimum required RPMs, you're in the clear. However, there is no argument whatsoever that too little RPM's = tumbling boolits or boolits that are not flying correctly.
I have actually used this principle very effectively to my advantage by shooting rifle boolits right at the ragged edge of the minimum RPM's so that they fly fairly well to the deer, but tumble like crazy as soon as they hit. Nothing like a 250 grain 35 caliber round nose doing a flip and exiting sideways to convince the average deer that life just aint worth living. LOL!

[mallen]

that's basically what is happening, although its being caused by leading. as it didn't start happening till the barrel leaded.

course, one of the ways to stop leading, is going faster. first i gotta figure out why my die is swagging the bullet down.

[leeggen]

One more thing is only change one thing at a time until you fix the problem!!!! If you change several at once then you don't and won't know which fix worked. It may take 1 change or it may take several one time changes. My duaghter in law wanted me to set up cast for her 9mm. I read and reread a huge number of threads on here before attempting. At present I have shot 100 rounds and at the point of no leading( also meanin very minor) and within about 1gr of powder as to where it is going to shoot cast. The biggest thing with 9mm is, read archives on the 9mm and pay attention to the ones that have already been threw the process. When you read the achives you will find the ones to listen to and then you must follow the directions. The 9mm is picky but listen to the ones already that have found the right path.
every pistol and rifle is alittle different but basicaly the same. I may have been lucky with mine, but again I read lots before even trying. I also load for my own 40S&W seems I have done fine with it also, but I followed the directions. Try starting by reading- Setting up for boolits in a 9mm-MTgun44, Btroj, Gearnasher and Char-gar and several others you will pickup on as you read these gentlemens threads on the 9mm.
Just my take on the 9mm.
Oh thanks gentlemen for your help.
CD

[btroj]

Here ya go, read this, it will help.

http://castboolits.gunloads.com/showthread.php?121737-Setting-up-for-boolits-in-a-new-9mm

[bugkiller]

This maybe really basic, but if your target is not on firm backing, the holes can LOOK like your bullet is tumbling when it is not. Paper target flapping off of a hanger is a prime example.

[mallen]

im pretty sure its just the leadding.

isnt there a chart that shows types of leadding and causes?

[leeggen]

Thanks Btroj I had the thread stored but could not find it.
Appreciate that. That needs to go to a sticky cause it is great way to start.
CD

[btroj]

Leggen, you aren't kidding. That is a well done, complete, concise write up on starting to load cast for a 9mm

[fredj338]

sdb is great for folks on a budget. I do plan on upping the powder once i see how it does if i can get the swagging done with. im affraid i do not understand your advice on polishing the expander. lowering the diameter, would make my case dia smaller, thus it would swag the bullet more?
Sorry, I wasn't clear. If you go with a larger expander for the lead bullets, you may have to polish one down for smaller jacketed.